Serum: Collect in a serum separator tube or red-top tube (no gel). The tube should be centrifuged after clotting. Spun serum separator tubes may be submitted at room temperature or refrigerated unopened without transfer to a plastic, screw-cap vial. Red-top tube (no gel) serum should be transferred to a plastic screw-cap vial and submitted for testing.

Plasma: Collect in an EDTA (lavender-top) tube and centrifuge within 24 hours of collection. Transfer plasma to a plastic, screw-cap vial, label as plasma, and submit for testing.

TB Testing (green lithium-heparin tube): Collect a minimum of 6 mL of blood by venipuncture into a lithium-heparin (green-top) tube. Gently mix by inverting several times to dissolve the heparin. Refrigerate at 2-8°C.